Recently saw the following posted by me number one battery Guru; and got to thinking that maybe we need thread – maybe even as a sticky.

Quote:

Originally Posted by everydayflyer

As I have posted in the past Pb is more complicated charging correctly than LiPolys.

Standard charge rate for flooded cell deep cycles is 1/3C .

Some can be charged much faster ,one of my sealed (AGM) 48Ah can be charged at 100 amps.
Best charger I am aware of is an Iota charger / power supply with a IQ4 Smart charge controller.

Bulk 2.46 per cell
Absorption 2.36
Float 2.26

FYI When the FMA engineer was developing the charging algoratims for the POWERLAB8 he found out very fast that routines used by most automobile chargers sucked big time and that it was common for the typical battery to fail in less than 100 cycles.

I use my IOTA 45 amp. with an external IQ4 Smart charge controller most of the time for my deep cycles.

Charles

In my case I have three Group 24 / 85AH Deep Cycle 12V Pbs (abbreviated from now on as DP) that I use primarily for Zip Charging my A123 powered planes: DP-2S for A123-6S & DP-3S for A123-10S.

I also use them to power my LiPo chargers – wired in P to keep use equalized.

For example yesterday I took out about 30AH and used two of them in combos of DP-2S & DP-2P.

I Bulked them as 2S to 28.8V @ 20 amps via my MasTech 5020; then as 2P with my Schulze 330s for Acceptance (it also seems to do Equalization). And then finally back on my Minder for float/desulfation.

Had hoped my new iC3010B would have been “smarter” than just a float charger

This is my 1st couple of weeks of doing this so no long term data yet.

Looks like you have a sound approach for long term good health and maximum capacity.

Since I only use my deep cycles on weekends, my approach is a little less involved. I simply strap them in parallel after a day of flying and connect them to my Battery Tender and it does all of the 'heavy lifting' for me. My deep cycles are always fully charged and ready to go when I hit the field. As Ron Popeil says..."set it and forget it".

I use the Junior which has listed bulk charge rate of .75A. This works perfectly for me as I only use my deep cycles on weekends and rarely pull over 40Ah out of each battery. Plug them in on either Saturday or Sunday evening and they're fully charged and ready to go by the following weekend. On rare circumstances that I am using a good portion of available capacity on consecutive days, I charge them with one of my iChargers.

I misplaced my gage and have not checked it in over two years now. Mine are 4 years old now and still doing OK but I have not done a capacity check on them since back in April or May.

Logic says they are living on borrowed time and if I was flying A123 and Zip charging like I was when they were new I would most likely have to replace them. Since chargers work fine down to 10V and they manage to hold 11V plus under my normal charging loads I may get another year or two out of them.

As far as I'm concerned, CTEK chargers are unrivaled when it comes to maintaining 12V lead-acid storage batteries. I say that as someone who has spent more than 25 years in the car, truck, industrial equipment, and recreational vehicle repair trades and my specialty in all those fields was electrical diagnosis and repair.

Look at the CTEK Multi US 7002 and the CTEK Multi US 25000 The first can charge at 7A, the second can charge at 25, and both can be used as 12V power supplies with no battery connected.

These chargers aren't cheap, but you can leave them connected to a battery indefinitely and they WON'T harm the battery. I have the 7002 and I just love it. It will easily charge my Group-27 105Ah deep cycle battery overnight and I just leave it connected if I'm not using the battery. My battery is one of the old fashion "flooded" types with removable caps to check the electrolyte and I haven't had to add any yet after nearly a year of maintaining it as I described with my CTEK.